MONDAY, April 11 (HealthDay News) -- A new study of middle-aged black women finds that almost 30 percent suffer from baldness and scarring in the center of their scalps, possibly because braids and weaves pull their hair too tight.

The study doesn't prove that black women's choices about hair grooming play a major role in whether they lose significant amounts of hair. However, the findings are enough to suggest that black women need to be cautious, said study lead author Dr. Angela Kyei, a dermatologist at the Cleveland Clinic.

"You have to stop and think about what you're doing with your hair, and you have to look at your children's hair," Kyei said. "African Americans begin putting relaxers and chemicals in their children's hair early. You have to start thinking about what might happen later on."

Baldness in the middle of the scalp is quite common among black women, Kyei said, but there hasn't been much research into what causes it.

In the past, dermatologists thought that hot combs or hair oils were the cause of the hair loss. Another suspect was the chemicals that black women use to relax their hair, turning it from curly to straight.

But, dermatologist Dr. Jerry Shapiro, a clinical professor of dermatology at the University of British Columbia who specializes in hair problems, said, "There are many women who use relaxers who don't have this problem."

One thing is clear about the baldness, however: "Once you get it, it's permanent," Kyei said, and the hair doesn't come back. "That's why a lot of African Americans wear wigs or put something on their scalp to hide their hair."

In the new study, Cleveland Clinic researchers examined the hair of 326 black women who were approached at churches and a health fair in Cleveland. The women answered questions about their hair and their health.

Twenty-eight percent of the women showed signs of hair loss in their central scalps. Of those, almost 60 percent had signs of severe hair loss. And those women were more likely to have type 2 diabetes, to have bacterial infections in their scalps and to have had hair styles like braids and weaves.

The culprit appears to be hair styles -- including extensions -- that pull the hair tightly, Kyei said. This causes scarring that leads to permanent hair loss.

The study doesn't point a finger at hair-relaxing products, but Shapiro said the jury's still out on their role in baldness.

So what should black women do?

"If you think that you're having hair loss, you need to have it evaluated to see if it's this type of hair loss," Kyei said. "If you're relaxing your hair, if you're having tight braids, I would just put that on hold until you find out what's going on with your hair."

You may wish to ask for a referral to a dermatologist who specializes in hair, Kyei said. While dermatologists are trained in treatment of skin, hair and nails, some focus specifically on hair. "Hair disorders are one of the hardest areas in dermatology, and it takes a lot of investigation to figure out what's going on," she said.

The study was published online April 11 in the journal Archives of Dermatology.

More information

Learn more about hair loss from the U.S. National Library of Medicine.